Test in IE11, but also in as many other browsers as possible
Create a Lessons page and add at least three items to it using the Add Content menu (e.g. text, links, quizzes) or go to any existing Lessons page that contains several items.
Click on Reorder.
Click on an item to move it, and drag it to a new position in the list.
Click on the same item you just moved, and move it again
If bug is present: some other item will disappear from the list entirely
Try to click and move any item in the list
If bug is present: you will not be able to move any items from this point on, clicking and dragging will only result in highlighting text
Verify that dragging items to the "delete area" still works
Verify that saving your new item order still works

Description

When using IE11, the "Reorder" functionality in Lessons is broken. The solution is to replace the Fluid JavaScript reorder with jQuery's, which also results in code reduction. The IE11 specific bug is detailed in the testing steps above.